With advantages of low drive voltage, high luminous brightness, high luminous efficiency, wide luminous viewing angle, high response speed, ultrathin shape, light weight and compatible flexible substrate, Organic Light-Emitting Diode (OLED) occupies an important position in the field of display.
The structure of the organic light-emitting diode usually includes a substrate, an anode, a Hole Injection Layer (HIL), a Hole Transport Layer (HTL), an Emitting Layer (EML), an Electron Transport Layer (ETL), an Electron Injection Layer (EIL) and a cathode which are arranged in sequence in an overlaying manner. The emitting unit of the structure can form an energy level state in a ladder form, such that the holes and electrons can be easily transported to the emitting layer, where the HIL, HTL, EML, ETL and EIL are all organic-material layers.
However in the current technologies, the drive voltage of the organic light-emitting diode is higher than previous display devices, the luminous efficiency is lower, and the performance of the organic light-emitting diodes needs to be further improved.